The question of John W. Hinckley Jr.'s sanity, debated for weeks by lawyers and experts, went to the jury yesterday, but no verdict was reached in nearly 3 1/2 hours of deliberation.

The jurors, seven women and five men, left the courthouse for the day at 7:20 p.m. They were taken by deputy U.S. marshals to an undisclosed location where they will be sequestered until they reach a decision in the case. Their deliberations are scheduled to resume at 8:30 a.m. today.

The question before them is whether Hinckley was legally insane on March 30, 1981, when he shot and wounded President Reagan and three others outside the Washington Hilton Hotel.

Hinckley could be sentenced to life in prison if he is convicted of the 13 criminal charges against him. Parker told the jury yesterday that if they find Hinckley "not guilty by reason of insanity," he will be committed by the court to St. Elizabeths Hospital, with a hearing to be held within 50 days to determine if he should be released. He would be entitled to release only if the court decided he was no longer a danger to himself or others as a result of mental illness.

Chief prosecutor Roger M. Adelman urged the jurors yesterday to reject Hinckley's insanity claim and to convict him because "the time has come for John Hinckley Jr., for the first time in his life, to take responsibility for what he has done."

Defense lawyer Vincent J. Fuller had tried earlier to persuade the jurors to set aside the emotional evidence about the shooting and to focus instead on Hinckley's state of mind when he fired on the president.

Adelman dramatically attacked Fuller's effort. The prosecutor, his voice filled with indignation as he began his final statement to the jury, centered on Reagan's press secretary James Brady, who suffered severe and lasting brain injury when he was shot in the head by exploding Devastator bullets fired by Hinckley.

"How dare he say to you . . . , 'Jim Brady, forget the Devastator bullets.' I defy him. I defy anybody to go up to the families of those victims--Mr. Brady and anybody else--and say, 'Forget those Devastator bullets.'

"You can't do that. You can't run. You can't hide. Oh, Mr. Hinckley would like to do that . . . . Mr. Hinckley has been avoiding responsibility all his life," Adelman said as he turned and pointed directly at Hinckley, who sat impassively at the defense table.

Fuller, completing his closing argument, told the jury that Hinckley, consumed by an "inner frenzy," was compelled to attack the president to "terminate his own existence and to accomplish his ideal union with Jodie Foster, whether it be in this world or the next."

Hinckley's "totally unrealistic, deluded goal" of a union with Foster, the actress he had pursued with love letters and telephone calls, so dominated his thinking that he could not abide by the law and could not appreciate that his acts were wrong, Fuller told the jury.

" . . . He was so involved in this commitment to this woman, Jodie Foster, that nothing else mattered but that he achieve this goal," Fuller said.

The dual questions of Hinckley's ability to abide by the law and to appreciate that his acts were wrong are at the heart of the jury's deliberations as they try to evaluate his state of mind when he fired on the president.

U.S. District Judge Barrington D. Parker instructed the jurors yesterday that, in the language of the law, they must return a verdict of "not guilty by reason of insanity" if they decide that, as a result of mental disease or defect, Hinckley "lacked the substantial capacity" to either "conform his conduct to the law" or "appreciate the wrongfulness of his conduct."

Reading from standard jury instructions used for insanity cases, Parker told the jury that the term "mental disease or defect" includes "any abnormal condition of the mind"--regardless of medical label--that "substantially affects mental or emotional processes and substantially impairs behavior controls."

During Hinckley's trial, the jury heard long testimony from psychiatrists for the prosecution and the defense who conducted scores of interviews with Hinckley after the shooting.

The defense doctors said Hinckley suffered from forms of schizophrenia, a serious mental illness, but the prosecution experts said that while he suffered from personality disorders and common depression, he was still in control of his conduct.

Yesterday, Parker gave the jury some guidance on how to evaluate expert testimony as they try to determine Hinckley's mental condition on the day of the offense.

He said they are not "bound by medical labels, definitions, or conclusions as to what is or is not a mental disease or defect."

Parker also told them they could consider testimony from lay witnesses who observed Hinckley's appearance and behavior. Parker advised them they are not restricted by testimony from either the experts or the lay witnesses, but that they should consider those opinions along with other evidence in the case.

As a general rule, juries are not told the consequences of their verdict in criminal cases. In insanity cases, however, the courts have said jurors can be told the effect of their verdict so they will know that their decision means confinement to a mental hospital, not freedom or imprisonment.